ava.lang.AssertionError: not a json object: null
at org.apache.calcite.adapter.druid.DruidQuery.writeObject(DruidQuery.java:860)
at org.apache.calcite.adapter.druid.DruidQuery.writeArray(DruidQuery.java:840)
at org.apache.calcite.adapter.druid.DruidQuery.writeObject(DruidQuery.java:856)
at org.apache.calcite.adapter.druid.DruidQuery.writeField(DruidQuery.java:826)
at org.apache.calcite.adapter.druid.DruidQuery.getQuery(DruidQuery.java:729)
at org.apache.calcite.adapter.druid.DruidQuery.deriveQuerySpec(DruidQuery.java:479)
at org.apache.calcite.adapter.druid.DruidQuery.getQuerySpec(DruidQuery.java:428)
at org.apache.calcite.adapter.druid.DruidQuery.deriveRowType(DruidQuery.java:322)
at org.apache.calcite.rel.AbstractRelNode.getRowType(AbstractRelNode.java:224)
at org.apache.calcite.plan.volcano.VolcanoPlanner.register(VolcanoPlanner.java:857)
at org.apache.calcite.plan.volcano.VolcanoPlanner.ensureRegistered(VolcanoPlanner.java:883)
at org.apache.calcite.plan.volcano.VolcanoPlanner.ensureRegistered(VolcanoPlanner.java:1769)
at org.apache.calcite.plan.volcano.VolcanoRuleCall.transformTo(VolcanoRuleCall.java:135)
at org.apache.calcite.plan.RelOptRuleCall.transformTo(RelOptRuleCall.java:225)
at org.apache.calcite.adapter.druid.DruidRules$DruidAggregateProjectRule.onMatch(DruidRules.java:448)
at org.apache.calcite.plan.volcano.VolcanoRuleCall.onMatch(VolcanoRuleCall.java:211)
at org.apache.calcite.plan.volcano.VolcanoPlanner.findBestExp(VolcanoPlanner.java:650)
at org.apache.calcite.tools.Programs$5.run(Programs.java:326)
at org.apache.calcite.tools.Programs$SequenceProgram.run(Programs.java:387)
at org.apache.calcite.prepare.Prepare.optimize(Prepare.java:162)
at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:295)
at org.apache.calcite.prepare.Prepare.prepareSql(Prepare.java:204)
at org.apache.calcite.prepare.CalcitePrepareImpl.prepare2_(CalcitePrepareImpl.java:783)
at org.apache.calcite.prepare.CalcitePrepareImpl.prepare_(CalcitePrepareImpl.java:639)
at org.apache.calcite.prepare.CalcitePrepareImpl.prepareSql(CalcitePrepareImpl.java:609)
at org.apache.calcite.jdbc.CalciteConnectionImpl.parseQuery(CalciteConnectionImpl.java:214)
at org.apache.calcite.jdbc.CalciteMetaImpl.prepareAndExecute(CalciteMetaImpl.java:595)
at org.apache.calcite.avatica.AvaticaConnection.prepareAndExecuteInternal(AvaticaConnection.java:615)
at org.apache.calcite.avatica.AvaticaStatement.executeInternal(AvaticaStatement.java:148)
at org.apache.calcite.avatica.AvaticaStatement.executeQuery(AvaticaStatement.java:218)
at org.apache.calcite.test.CalciteAssert.assertQuery(CalciteAssert.java:511)
at org.apache.calcite.test.CalciteAssert$AssertQuery.queryContains(CalciteAssert.java:1422)
at org.apache.calcite.test.DruidAdapterIT.testNotAcceptedKindOfExtract(DruidAdapterIT.java:1996)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:237)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)